Work identification system and signature management system

ABSTRACT

A work identification system comprises a work storage configured to store digital data representing at least one of a shape, area, and color of an only one work, a collation section configured to calculate a degree of deviation between digital data representing at least one of a shape, area, and color of a target work to be identified and the digital data stored in the work storage, and a test section configured to perform a test of hypothesis based on a predetermined hypothesis using the degree of deviation.

TECHNICAL FIELD

[0001] The present invention relates to a system for identifying aspecific work of art (the only one work that exists in the world) suchas a picture or a photograph and a signature management system formanaging a signature of a work of art (hereinafter simply referred to asa “work”).

BACKGROUND ART

[0002] An identification system according to the present inventionjudges the identity between a number of reference works and only onework, from amongst works of art, crafts, antiques, jewels, such aspictures, photographs, block prints, pasted pictures, sculptures,statues, pots, earthenware, calligraphy, a created shape, object orshape formed by an artist, thereby making it possible to identify thecreator of the work from the judgment result or search for the mostsimilar work. In particular, attention is paid to the signature of thework, whereby precise judgment of the work's identity can be performedwith the smallest amount necessary of digital data.

[0003] The present method for verifying a specific work of art or theauthor is mainly achieved by visual inspection, knowledge, or experienceof an expert in the field, or by the creator themselves. Therefore, theauthor of the work sometimes cannot be identified preciously, or cannotbe done so immediately. In addition, even if an attempt is made toidentify a work, such an identification method is difficult to master,and is not obvious to everyone.

[0004] For example, assume that a photograph of a work “A” is includedin a yearbook of arts & crafts. When a work “B” appears, the work “B” isphotographed, and is compared with work “A” of the yearbook. If theseworks are identical to each other, the works “A” and “B” can beidentified to be the same works, and the author of the work “B” can beidentified to be the author of the work “A” in the yearbook.

[0005] However, even if the works “A” and “B” are identical, it isdifficult to physically evaluate the photography methods and conditionsof the works “A” and “B”. Thus, precise identification is difficult.

[0006] Examples of differences produced because of photography are shownbelow.

[0007] Example 1: As pigments in pictures of works degrade with thelapse of time, color fading or color changes may occur. When the sameworks are photographed at different times, a difference in color occurs.

[0008] Example 2: The change light of the photography conditions, causedby reflection or refraction. Even if the conditions such as atmospheric,light, color temperature, type of lenses used, relative position of aprojection face relevant to the work, etc. are reproduced, a differencestill occurs with the shape, area, and color of the photograph produced.

[0009] Therefore, even if the works “A” and “B” are identical to eachother, when the photographic work “A” is compared simply with that ofthe work “B”, a differences exist between them, thus making it difficultto indicate the identicalness of works “A” and “B”.

[0010] In addition, at present, there is a database for searching forworks with a character string such as work name or author's name definedas a key. However, in the case where a work is present at hand, but thework name or author's name is unknown, even if an extensive search isconducted the work name or author may not necessarily be found.

[0011] In such a conventional work identity judgment system, a moreprecise method of verification is requested irrespective of aninspection, knowledge or experience of an expert in the field, or thecreator of the work.

[0012] In addition, if the work name or author's name is unknown, it isdifficult to conduct a search for the work as no parameters areavailable.

[0013] In addition, at present, a number of digital images of works suchas photographs are used, and the digital images are distributed via theInternet. However, no signature is attached to these distributed imagesin advance. No signature is inserted into and distributed to a positiondetermined when digital images and digitized signatures are provided,and digital images are distributed.

DISCLOSURE OF INVENTION

[0014] Accordingly, the present invention is directed to method andapparatus that substantially obviates one or more of the problems due tolimitations and disadvantages of the related art.

[0015] According to one aspect of the present invention, there isprovided a work identification system comprising:

[0016] a work storage configured to store digital data representing atleast one of a shape, area, and color of an only one work;

[0017] a collation section configured to calculate a degree of deviationbetween digital data representing at least one of a shape, area, andcolor of a target work to be identified and the digital data stored inthe work storage; and

[0018] a test section configured to perform a test of hypothesis basedon a predetermined hypothesis using the degree of deviation.

[0019] According to another aspect of the present invention, there isprovided a signature management system comprising:

[0020] a signature storage configured to store signature datarepresenting signatures;

[0021] a work storage configured to store work data representing works;and

[0022] a signature inserting section configured to insert one of thesignature data into one of the work data in response to a requestreceived through a network from a requester and distribute the work datainto which the signature data is inserted to the requester through thenetwork.

[0023] According to still another aspect of the present invention, thereis provided a signature management system comprising:

[0024] a signature storage configured to store signature datarepresenting signatures; and

[0025] a signature identifying section configured to collate an objectsignature data transmitted from a requester through a network and thesignature data stored in the signature storage and return a result ofcollation to the requester through the network.

[0026] According to one aspect of the present invention, the workidentification system electronically judges the identity of an only onework.

[0027] According to another aspect of the present invention, thesignature management system electronically manages a signature of awork.

[0028] According to still another aspect of the present invention, thesignature management system is capable of, before a digitized work isdistributed, determines a proper position for inserting the signature ona digitized work, inserts the signature in that position and, anddistributes the signature inserted work.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1 is a block diagram of a work identification systemaccording to a first embodiment of the present invention;

[0030]FIG. 2 is a flowchart of an identity judgment procedure based onthe forms of signature “A” and signature “B”;

[0031]FIG. 3A is a view showing a closed curve Ad that forms asignature;

[0032]FIG. 3B is a view illustrating a spline interpolation of theclosed curve;

[0033]FIG. 4 is a flowchart of an identity judgment procedure based onthe areas for signature “A” and signature “B”;

[0034]FIG. 5 is a flowchart of an identity judgment procedure based onthe colors of signature “A” and signature “B”;

[0035]FIG. 6 is a block diagram of a basic configuration of a worksignature management system according to a second embodiment of thepresent invention;

[0036]FIG. 7A is a flowchart of the steps for storing an electronicindependent signature according to the second embodiment;

[0037]FIG. 7B is a flowchart of the steps for storing an electronicspecific signature according to the second embodiment;

[0038]FIG. 7C is a flowchart of the steps for storing an electronic workaccording to the second embodiment;

[0039]FIG. 8 is a flowchart of the steps for inserting an electronicindependent signature according to the present embodiment;

[0040]FIG. 9A is a flowchart of the steps for searching for anelectronic signature according to the second embodiment;

[0041]FIG. 9B is a flowchart of the steps for searching for anelectronic work according to the second embodiment;

[0042]FIG. 10A is a flowchart of the steps for judging the identity ofan electronic signature according to the second embodiment; and

[0043]FIG. 10B is a flowchart of the steps for judging the identity ofan electronic work according to the second embodiment.

BEST MODE FOR CARRYING OUT OF THE INVENTION

[0044] Hereinafter, embodiments of the present invention will bedescribed with reference to the accompanying drawings.

First Embodiment

[0045] A work identification system for judging identity based ondigital data of a specific work will be described in accordance with afirst embodiment. Judgment of identity is performed when at least one ofthe shape, area, and color of a signature is defined as a judgmentreference by using digital data of only a signature assigned to a work,instead of using digital data of the entire work. The degree ofdeviation in shape, the degree of deviation in area, and the degree ofdeviation in color are calculated, and the calculated degree ofdeviation is compared with a reference value, thereby making it possibleto electronically identify a difference caused by a difference inphotography conditions and photography equipment during electronicrepresentation even in the same signatures with a difference between asignature of one work and another signature of a similar work. A test ofhypothesis is used to obtain the result of identification.

[0046] The definitions of words used in the present invention will bedescribed.

[0047] Only One Work: The singular work that exist in the world. Thisoften denotes articles represented by works of art, crafts, antiques,jewels, such as pictures, photographs, block prints, pasted pictures,sculptures, statues, pots, earthenware, or calligraphy, a created shape,an object or shape formed by hand. The signature given to a work by theauthor corresponds that work only, and exists in a unique form. Thus, asignature can be used in order to identify the identity of only onework.

[0048] Projection: Converting information in one space into informationin another space. For example, projecting an object in three-dimensionalspace by an analogue camera denotes projecting into a two-dimensionalplane on a film. Projecting an object in three-dimensional space by adigital camera or scanner denotes projecting into a pixel plane that isa two-dimensional plane. Projecting a cross section of an object inthree-dimensional space denotes projecting into a two-dimensional plane.Projecting into three-dimensional space is possible by projecting thecross section of an object in three-dimensional space a plurality oftimes. An object in a three-dimensional space is projected at a varietyof angles, thereby enabling projection into three-dimensional space.Expressing an object in three-dimensional space as a two-dimensionalfunction denotes projecting into a two-dimensional plane. Expressing anobject in three-dimensional space as a three-dimensional functiondenotes projecting into three-dimensional space. Expressing data in atwo-dimensional pixel plane as a two-dimensional function denotesprojecting into a two-dimensional plane.

[0049] Digital Data: Digitized information. Images in a pixel plane,points, functions or the like in a two-dimensional plane areexemplified, but not limited thereto, and information expressed by acombination of numerals can be employed.

[0050] Hereinafter, a first embodiment of the present invention will bedescribed in detail.

[0051]FIG. 1 is a block diagram showing a basic configuration of a workidentification system according to the present invention.

[0052] Only one work is converted into electronic digital data fromwhich information such as shape, area, and color can be derived. A workidentity judgment system according to the present invention comprises anonly one work storage section 1 including a memory for registering andstoring digital data on such only one work as input F in advance; atarget work storage section 2 including a memory for temporarily storingsimilar digital data on a work to be identified as input G; a collationsection 3 including an electronic computing circuit and a program forextracting, comparing, and collating electronic digital data on theshape, area, and color from digital data stored in the only one workstorage section 1 and the target work storage section 2 and computingthe degree of deviation; a reference value storage section 4 including amemory capable of storing sample means and sample variances forpopulations; a hypothesis test section 5 including a computing circuitand a program for performing a test of hypothesis using the degree ofdeviation outputted from the collation section 3 using a reference valueselected based on a selection signal; and an output section 6 includingan output circuit for outputting the result of test obtained by thehypothesis test section 5 as an electronic signal. The system maycomprise a transmission circuit for transmitting an electronic signalfrom the output circuit 6 to an electronic network or the like asrequired, and a display device connected to the output circuit 6. Theseonly one work storage section 1, target work storage section 2,collation section 3, reference value storage section 4, hypothesis testsection 5, and output section 6 can be achieved by one computer and aprogram or can be achieved by connecting a plurality of computers toeach other via an electronic network.

[0053] Digital data on only one work and a work to be identified isstored in the only one work storage section 1 and target work storagesection 2 as digital data from which information on shape, area, orcolor is derived. The degree of deviation in the works is calculated bymeans of the collation section 3 as shape function data in a pluralityof divided regions, color data in a plurality of divided regions, andarea data in a plurality of divided regions. The test of hypothesis isperformed based on the degree of deviation using the sample mean orsample variance. The result of test is outputted to the output section6, thereby electronically verifying a work.

[0054] In the case where an attempt is made to search for a work orsignature, the degree of deviation between digital data stored in thetarget work storage section 2 and all the digital data contained in thestorage section 1 is calculated by means of the collation section 3. Thecalculated degree of deviation is subjected to a test of hypothesis bythe hypothesis test section 5. Then, a similar work is electricallysearched from the test result, and the result is outputted to the outputsection 6.

[0055] In the present embodiment, it is determined whether or notsignature “A” and signature “B” are identical to each other by usingthree electronic references; shape, area, and color. The respectivedegrees of deviation are electronically calculated relevant to thesethree criteria of signature “A” and signature “B”, thereby performingidentification.

[0056] The three references are common in that two signatures areprojected in a two-dimensional plane and the projection result of thetwo signatures is digitized. It is assumed that a difference occurs withprojection. A kind of hypothesis test which can be used depends onwhether or not the difference caused by the projection follows normaldistribution.

[0057] In comparing the result obtained by projecting signature “A” ontothe two-dimensional plane with the result obtained by projectingsignature “B” onto the two-dimensional plane, even if the signatures “A”and “B” are identical to each other, it is difficult to equalize theprojection methods or projection conditions. Thus, a difference alwaysoccurs with the projection result. The differences are exemplified asfollows.

[0058] (1) Degradation of work with an elapse of time

[0059] Color fading or change of color may occur with a pigment in apicture with the elapse of time after being produced. If projection isperformed for the same signature at a different time, a differenceoccurs in color.

[0060] (2) Change of projection conditions

[0061] Light is prone to reflection and refraction. If there arecompletely reproduced the state of air at a projection site, the stateof the rays of light, color temperature, individual difference in lensesused for projection, a relative position of a projection plane relevantto a signature or the like, a difference occurs with the shape, area,and color of the projection result.

[0062] In most cases, even if signature “A” and signature “B” areidentical to each other, in simply comparing the projection result ofsignature “A” with the projection result of signature “B”, a differenceoccurs with the result of projection, thus making it difficult to judgethat signature “A”, and signature “B” are identical to each other.Therefore, it is difficult to determine that the two signatures “A” and“B” are identical based on a mere comparison result. According to thepresent invention, it is assumed that the degree of deviation of the twodifferent signatures “A” and “B” is far greater than the degree ofdeviation of the two signatures which are the same but projected atdifferent conditions.

[0063] If the degree of deviation is large, the degree of deviation isdistributed over the wide range. It is required that the degree ofdeviation follows the normal distribution in order to test the largedegree of deviation.

[0064] If the average of the degree of deviation is large, the degree ofdeviation is large. The degree of deviation is treated as a distancewithout the direction (or sign) so that the degree of deviation must bean absolute value. This is because that a positive degree of deviationand a negative degree of deviation are cancelled and the average valuethereof becomes zero in spite of a large degree of deviation.

[0065] It is possible to determine whether the degree of deviation isbased on the projection condition by performing a test of hypothesisusing a variance or mean of the degree of deviation. If it is determinedthat the degree of deviation is based on the projection condition, itcan be determined that the signatures “A” and “B” are identical to eachother. Otherwise, it can be determined that these signatures “A” and “B”are not identical to each other.

[0066] In the present embodiment, although digital data stored in theonly one work storage section 1 and target work storage section 2 isdefined as image data, and digital data on shape, area, and color iscalculated from such image data before computing the degree ofdeviation, the digital data stored in the only one work storage section1 and target work storage section 2 may be digital data by which digitaldata on the shape, area, and color of signature can be calculatedwithout being limited thereto.

[0067] For example, as long as digital data stored in the only one workstorage section 1 and target work storage section 2 is directed todigital data on the shape, area and color calculated from image data,and the digital data is generated by using a predetermined method, thereis no need for the collation section 3 to calculate digital data onshape, area, and color, and the degree of deviation is merely calculatedbased on the digital data stored in the only one work storage section 1and target work storage section 2.

[0068] Now, computation of the degree of deviation in shape and judgmentof identity will be described here.

[0069] A certain shape of a signature can be regarded as a set of closedcurves, a curve at the contour line of that signature is a closed curve,and this closed curve can be mathematically expressed as a function.This function closely represents the shape of a signature.

[0070] Comparing signature “A” with signature “B” indicates comparingthe result obtained by projecting signature “A” onto the two-dimensionalplane with the result obtained by projecting signature “B” onto thetwo-dimensional plane.

[0071] The function of the closed curve of the signatures “A” and “B” isrepresented by digital data. Here, the closed curve for each of thesignatures “A” and “B” is represented by N number of dots and the dotsare interpolated by a parametric spline interpolation. Generally, anarbitral-closed curve can be expressed by a parametric splineinterpolation function obtained by a parametric spline interpolationusing a parametric variable. The parametric spline function is a (2M−1)order function passing the data points on the predetermined closed curve(M is an arbitrary positive integer).

[0072] In order to express an arbitrary closed curve in the X-Ytwo-dimensional plane by a function, the parametric spline interpolationis performed as follows. The parametric spline interpolation uses aparametric variable t. Thus, the closed curve can be expressed by asmooth function and numerically analyzed such as a differentiation.

[0073] N number of data points (x(t_(i)), y(t_(i))) (i=0, 1, 2, . . .N−1) are positioned on the curve. Here, (x(^(t)N−1), y(^(t)N−1))=(x(t₀),y(t₀)). It is assumed that the parameter t(0≦t≦N−1) is t_(i)=i(i=0, 1,2, . . . N−1). Then, the parametric spline interpolation function isexpressed as a first-order combination of a B-spline function. TheB-spline function of (K−1)th order is expressed by the followingrecurrence formula: ${B_{i,1}(t)} = \left\{ {{\begin{matrix}1 & \left( {q_{i} \leq t < q_{i + 1}} \right) \\0 & \left( {{t < q_{i}},{t \geq q_{i + 1}}} \right)\end{matrix}{B_{i,K}(t)}} = {{\frac{t - q_{i}}{q_{i + K - 1} - q_{i}}{B_{i,{K - 1}}(t)}} + {\frac{q_{i + K} - t}{q_{i + K} - q_{i + 1}}{B_{{i + 1},{K - 1}}(t)}}}} \right.$

[0074] Here, q is a node and can be derived from the value of the datapoint.

[0075] The parametric spline function of (2M−1)th order can be expressedas follows:${x(t)} = {\sum\limits_{i = 0}^{N - 2}{\alpha_{i - M}{B_{{i - M},{2M}}^{C}(t)}}}$${y(t)} = {\sum\limits_{i = 0}^{N - 2}{\beta_{i - M}{B_{{i - M},{2M}}^{C}(t)}}}$Here, ${B_{{i - M},{2M}}^{C}(t)} = \left\{ \begin{matrix}{{B_{{i - M},{2M}}(t)} + {B_{{i + N - M - 1},{2M}}(t)}} & \left( {0 \leq i \leq {M - 1}} \right) \\{B_{{i - M},{2M}}(t)} & \left( {M \leq i \leq {N - M - 1}} \right) \\{{B_{{i - M},{2M}}(t)} + {B_{{i - N - M + 1},{2M}}(t)}} & \left( {{N - M} \leq i \leq {N - 2}} \right.\end{matrix} \right.$

[0076] Coefficients α and β are obtained by inputting the value of thedata point to the function.

[0077] The degree of deviation between a differential value of Fth order(F is an arbitrary positive integer) of a function representing theclosed curve of a signature “A” and that of a signature “B”. It isdetermined using a test of hypothesis whether or not the degree ofdeviation is based on the projection. Stated another way, it isdetermined whether the degree of deviation is based on the projection orthe degree of deviation is due to the different signatures.

[0078] In order to perform the test of hypothesis, the following twohypothesizes are introduced:

[0079] (1) H₀ (null hypothesis): It is assumed that the degree ofdeviation is based on the projection.

[0080] (2) H₁ (alternative hypothesis): It is assumed that the degree ofdeviation is due to the different signatures.

[0081] Population is determined. A significance level and a criticalregion are determined in accordance with the object of the test, i.e.,identification judgment or similar work search. The final result isexpressed as follows. If the null hypothesis H₀ is rejected with asignificance level of 1%, the degree of deviation cannot be said to bethe degree of deviation based on the projection with an accuracy of 99%or more. If the null hypothesis H₀ is not rejected with a significancelevel of 1%, the degree of deviation cannot be said not to be the degreeof deviation based on the projection.

[0082]FIG. 2 is a flowchart of an identity judgment procedure based onthe shapes of signature “A” and signature “B”. Steps S5100 to S5160 areperformed at the collation section 3, but steps S5100 to S5150 may beperformed at the stage of digital data generation. Step S5180 isperformed at the hypothesis test section 5.

[0083] At step S5100, signature “A” or signature “B” is expanded orcontracted so as to make signature “A” and signature “B” comparable witheach other by a method for equalizing widths or heights of signature “A”and signature “B” or widths and heights of the signatures, or productsof the widths and heights thereof.

[0084] At step S5110, a center point C^((A)) is obtained from the widthand height of signature “A”. A center point C^((B)) is obtained from thewidth and height of signature “B”. The C^((A)) and C^((B)) are definedas an origin (0, 0) in an X-Y two-dimensional plane, respectively.

[0085] At step S5120, D number of closed curves of signature “A” aredefined as Ad (d=1, 2, 3, . . . D); D number of closed curves ofsignature “B” that corresponds to Ad are defined as Bd; a closed curvelength of the closed curve Ad is defined as L^((A)) _(d); and a closedcurve length of the closed curve Bd is defined as L^((B)) _(d).

[0086] An example of dividing a signature of a person “ai” into threeclosed curves is shown in FIG. 3A. At step S5130, as shown in FIG. 3B,(N+1) number of data points P^((Ad)) _(i)(i=0, 1, 2, . . . N) are set toequally divide the closed curve length L^((A)) _(d) of the closed curveAd or a total length ΣL^((A)) _(d)(d=1 to D) of the closed curve Ad. Forthe sake of simplicity, it is assumed that D=one, i.e., the number ofclosed curve is one. The coordinate values of the data points P^((Ad))_(i) are represented by P^((Ad)) _(i)=(x(t_(i)), y(t_(i))) (i=0, 1, 2, .. . N). Here, P^((Ad)) _(N)=P^((Ad)) ₀. The parameter t(0≦t≦N) isdefined as t_(i)=i(i=0, 1, 2, . . . N) at data points P^((Ad)) _(i)(i=0,1, 2, . . . N).

[0087] A point on the closed curve Bd, which is the closest to a startpoint P^((Ad)) ₀ of the closed curve Ad is defined as P^((Bd)) ₀. Aseries of data points P^((Bd)) _(i)(i=0, 1, 2, . . . N) includingP^((Bd)) ₀ and which equally divide the length L^((B)) _(d) of theclosed curve Bd is obtained. The coordinates of the respective pointsare defined as P^((Bd)) _(i)=(x(t_(i)), y(t_(i))) (i=0, 1, 2, . . . N).Here, P^((Bd)) _(N)=P^((Bd)) ₀. The parameter t(0≦t≦N) is defined ast_(i)=i(i =0, 1, 2, . . . N) at data points P^((Bd)) _(i)(i=0, 1, 2, . .. N).

[0088] At step S5140, a parametric spline interpolation is performed at(N+1) number of data points P_(i)(i=0, 1, 2, . . . N) to obtainparametric spline interpolation functions is performed x(t) and y(t).

[0089] At step S5150, functions of the closed curve Ad are defined asx^((Ad))(t), y^((Ad))(t), and functions of closed curve Bd are definedas x^((Bd))(t), y^((Bd))(t). Intervals t_(i)≦t≦t_(i+1) (i=0, 1, 2, . . ., N−2) of parameters are equally divided into J, and a parameter s(0≦s≦N×J−J) is newly taken provided:$S_{j} = {\frac{j}{J}\left( {{j = 0},1,2,{{\ldots \quad N \times J} - J}} \right)}$

[0090] where t_(i)=S_(i)×J(i=0, 2, 3, . . . N−1).

[0091] At step S5160, at each s_(j)(j=0, 1, 2, . . . N×J−J·1), thefollowing degree of deviation (distance) at points between closed curveAd and closed curve Bd is obtained:

ΔL _(d)(s _(j))={square root}{square root over ((x ^((Bd))(s _(j))−x^((Ad))(s _(j)))²+(y ^((Bd))(s _(j))−y ^((Ad))(s _(j)))²)}

[0092] The degree of deviation in 0th order differential value of x(s)and the degree of deviation in 0th order differential value of y(s) areobtained as follows:

Δx _(d)(s _(j))=x ^((Bd))(s _(j))−x ^((Ad))(s _(j))

Δy _(d)(s _(j))=y ^((Bd))(s _(j))−y ^((Ad))(s _(j))

[0093] The degree of deviation in first order differential value of x(s)and the degree of deviation in first order differential value of y(s)are obtained as follows:

Δx _(d′)(s _(j))=x ^((Bd)′)(s _(j))−x ^((Ad)′)(s _(j))

Δy _(d′)(s _(j))=y ^((Bd)′)(s _(j))−y ^((Ad)′)(s _(j))

[0094] The degree of deviation in second order differential value ofx(s) and the degree of deviation in second order differential value ofy(s) can be obtained as follows:

Δx _(d″)(s _(j))=x ^((Bd)″)(s _(j))−x ^((Ad)″)(s _(j))

Δy _(d″)(s _(j))=y ^((Bd)″)(s _(j))−y ^((Ad)″)(s _(j))

[0095] The degree of deviation in Fth order differential value of x(s)and the degree of deviation in Fth order differential value of y(s) canbe obtained as follows:

Δx _(d) ^((F))(s _(j))=x ^((Bd)) ^((F)) (s _(j))−x ^((Ad)) ^((F)) (s_(j))

Δy _(d) ^((F))(s _(j))=y ^((Bd)) ^((F)) (s _(j))−y ^((Ad)) ^((F)) (s_(j))

[0096] The features of the shape of a curve are well represented by thefirst order differential value.

[0097] Thus, the first order differential values are obtained in stepS5160.

[0098] At step S5180, a test of hypothesis is performed as follows.

[0099] (1) The population is defined by the degree of deviations x'(s)and y'(s) for the same signature under the different projectionconditions. It is assumed that the population follows the normaldistribution.

[0100] 50 sample points are defined in the signature so that 100 degreesof deviations x'(s) and y'(s) are defined as samples. A sample varianceis calculated. It is assumed that the sample variance is 0.0002. Thereference value storage section 4 stores the variances for everypopulation, e.g., the shape, area, color, first differential value,etc.. The variance for that population is assumed to be 0.0001 (which isread out from the reference value storage section 4). The test is todetermine whether or not the present sample variance 0.0002 issignificantly larger than the past variance 0.0001 with the significantlevel of 1%.

[0101] (i) H₀ (null hypothesis): σ² (population variance of the degreeof deviation)=0.0001.

[0102] (ii) H₁ (alternative hypothesis): σ²>0.0001. that the degree ofdeviation is due to the different signatures.

[0103] The critical value of σ² is calculated based on the past samplevariance (0.0001), χ²0.01(99) (which is a value of a significant levelof 1% under χ² distribution with 99 degrees of freedom), and the numberof samples (100) as follows: $\begin{matrix}{\quad {0.0001 \times \chi^{2}0.01{(99)/\left( {100 - 1} \right)}}} \\{= \quad {0.0001 \times {134.63/99}}} \\{= \quad 0.00013}\end{matrix}$

[0104] Since the present variance 0.0002 is larger than the criticalvalue 0.00013, null hypothesis H₀ is rejected. Therefore, it cannot besaid that the degree of deviation is based on the projection.

[0105] (2) The population is defined by the degree of deviations x'(s)and y'(s) for the same signature under the different projectionconditions. It does not matter whether or not the population follows thenormal distribution.

[0106] 50 sample points are defined in the signature so that absolutevalues of 100 degrees of deviations |x'(s)| and |y'(s)| are defined assamples. A sample mean is calculated. It is assumed that the sample meanof the degrees of deviation of 50 samples is 0.048 and the samplevariance of the degrees of deviation of 50 samples is 0.01. Thereference value storage section 4 stores the variances and means forevery population, e.g., the shape, area, color, first differentialvalue, etc.. The past mean for that population is assumed to be 0.045(which is read out from the reference value storage section 4). The testis to determine whether or not the mean 0.048 is significantly largerthan the past mean 0.045 with the significant level of 1%.

[0107] (i) H₀ (null hypothesis): μ (population mean of the degree ofdeviation)=0.045.

[0108] (ii) H₁ (alternative hypothesis): μ=0.045.

[0109] The critical value of μ is calculated based on the past mean(0.045), z(0.01) (which is a value of a significant level of 1% undernormal distribution), sample variance (0.01), and the number of samples(100) as follows: $\begin{matrix}{\quad {0.045 + {{z(0.01)} \times \left( {0.01/100} \right)^{1/2}}}} \\{= \quad {0.045 + {0.496 \times 0.01}}} \\{= \quad 0.04996}\end{matrix}$

[0110] Since the mean 0.048 is not larger than the critical value0.04996, null hypothesis H₀ is not rejected. Therefore, it cannot besaid that the degree of deviation is not based on the projection.

[0111]FIG. 2 shows the identity determination. Another example forsearching for the similar work will be described.

[0112] (1) H₀ (null hypothesis): It is assumed that the degree ofdeviation is due to the different (but similar) signatures of the sameauthor.

[0113] (2) H₁ (alternative hypothesis): It is assumed that the degree ofdeviation is significantly larger than the degree of deviation due tothe different (but similar) signatures of the same author.

[0114] The population is defined by the degree of deviations x'(s) andy'(s) for the similar signatures of the same person.

[0115] 50 sample points are defined in the signature so that 100 degreesof deviations x'(s) and y'(s) are defined as samples. A sample varianceis calculated. It is assumed that the sample variance of the degrees ofdeviation of 50 samples is 0.121. The past variance for that populationis assumed to be 0.1 (which is read out from the reference value storagesection 4). The test is to determine whether or not the variance 0.121is significantly larger than the past variance 0.1 with the significantlevel of 1%.

[0116] (i) H₀ (null hypothesis): σ²=0.1.

[0117] (ii) H₁ (alternative hypothesis): σ²>0.1.

[0118] The critical value of σ² is calculated based on the past variance(0.1), χ²0.01(99) (which is a value of a significant level of 1% underχ² distribution with 99 degrees of freedom), and the number of samples(100) as follows: $\begin{matrix}{\quad {0.1 \times \chi^{2}0.01{(99)/\left( {100 - 1} \right)}}} \\{= \quad {0.1 \times {134.63/99}}} \\{= \quad 0.136}\end{matrix}$

[0119] Since the present variance 0.121 is not larger than the criticalvalue 0.136, null hypothesis H₀ is not rejected. Therefore, it cannot besaid that the degree of deviation is not the degree of deviation betweentwo different but similar signatures of the same author.

[0120] Now, computation and identification of the degree of deviation inan area will be described.

[0121] An area for a signature can be expressed in a number of pixels.Comparing signature “A” and signature “B” denotes comparing an area ofthe result obtained by projecting signature “A” onto a two-dimensionalplane, then further projected onto a pixel plane with an area of theresult obtained by projecting signature “B” onto a two-dimensionalplane, further similarly projected onto a pixel plane.

[0122]FIG. 4 is a flowchart of an electronic identity judgment procedurebased on areas for signature “A” and signature “B”. Steps S6100 to S6140are performed at the collation section 3, but steps S6100 to S6130 maybe performed at the stage of generating digital data. Step S6150 andstep S6160 are performed at the hypothesis test section 5.

[0123] At step S6100, signature “A” or signature “B” is enlarged orreduced, thereby making signature “A” and signature “B” comparable witheach other using a method for equalizing the widths or heights ofsignature “A” and signature “B”, the widths and heights of thesignatures, or, products of the widths and heights thereof.

[0124] At step S6110, a frame of a rectangle is generated on a pixelplane, and the frame of the rectangle is divided into L square orrectangle lattices.

[0125] At step S6120, when signature “A” and signature “B” are appliedto the rectangle frame, numbers 1, 2, 3, . . . M are assigned tolattices in which even one pixel exists in the signature “A” orsignature “B”.

[0126] At step S6130, an area of a signature on a lattice m(m=1, 2, 3, .. . M) corresponds to the number of pixels of a signature on lattice “m”(m=1, 2, 3, . . . M). The number of pixels of signature “A” on thelattice m(m=1, 2, 3, . . . M) is defined as S_(Am)(m=1, 2, 3, . . . M),and the number of pixels of signature “B” on the lattice m(m=1, 2, 3, .. . M) is defined as S_(Bm)m(m=1, 2, 3, . . . M).

[0127] At step S6140, the degree of deviation in areas for signature “A”and signature “B” on lattice “m” (m=1, 2, 3, . . . M) is calculated byΔS_(m)=S_(Bm)−S_(Am)(m=1, 2, 3, . . . M).

[0128] At step S6150, a test of hypothesis is performed as follows.

[0129] (1) The population is defined by the degree of deviation ΔS_(m)for the same signature under the different projection conditions. It isassumed that the population follows the normal distribution.

[0130] 100(=10×10) sample points are defined in the signature so that100 degrees of deviations ΔS_(m) are defined as samples. A samplevariance is calculated. It is assumed that the sample variance is0.0015. The past variance for that population is assumed to be 0.0008(which is read out from the reference value storage section 4). The testis to determine whether or not the present sample variance 0.0015 issignificantly larger than the past variance 0.0008 with the significantlevel of 1%.

[0131] (i) H₀ (null hypothesis): σ²=0.0008.

[0132] (ii) H₁ (alternative hypothesis): σ²>0.0008.

[0133] The critical value of σ² is calculated based on the past variance(0.0008), χ²0.01(99) (which is a value of a significant level of 1%under χ² distribution of 99 degrees of freedom), and the number ofsamples (100) as follows: $\begin{matrix}{\quad {0.0008 \times \chi^{2}0.01{(99)/\left( {100 - 1} \right)}}} \\{= \quad {0.0008 \times {134.63/99}}} \\{= \quad 0.00109}\end{matrix}$

[0134] Since the present variance 0.0015 is larger than the criticalvalue 0.00109, null hypothesis H₀ is rejected. Therefore, it cannot besaid that the degree of deviation is based on the projection.

[0135] (2) The population is defined by the absolute value of degree ofdeviation |ΔS_(m)| for the same signature under the different projectionconditions. It does not matter whether or not the population follows thenormal distribution.

[0136] 100(=10×10) sample points are defined in the signature so that100 degrees of deviations |ΔS_(m)| are defined as samples. A sample meanof the degrees of deviation of 100 samples is calculated. It is assumedthat the sample mean is 0.048 and the sample variance is 0.01. The pastmean for that population is assumed to be 0.045 (which is read out fromthe reference value storage section 4). The test is to determine whetheror not the mean 0.048 is larger than the past mean 0.045 with thesignificant level of 1%.

[0137] (i) H₀ (null hypothesis): μ=0.045.

[0138] (ii) H₁ (alternative hypothesis): μ>0.045.

[0139] The critical value of μ is calculated based on the past mean(0.045), z(0.01), sample variance (0.01) and the number of samples (100)as follows: $\begin{matrix}{\quad {0.045 + {{z(0.01)} \times \left( {0.01/100} \right)^{1/2}}}} \\{= \quad {0.045 + {0.496 \times 0.01}}} \\{= \quad 0.04996}\end{matrix}$

[0140] Since the mean 0.048 is larger than the critical value 0.04996,null hypothesis H₀ is not rejected. Therefore, it cannot be said thatthe degree of deviation is not based on the projection.

[0141]FIG. 4 shows the identity determination. Another example forsearching for the similar work will be described.

[0142] (1) H₀ (null hypothesis): It is assumed that the degree ofdeviation is due to the different (but similar) signatures of the sameauthor.

[0143] (2) H₁ (alternative hypothesis): It is assumed that the degree ofdeviation is significantly larger than the degree of deviation due tothe different (but similar) signatures of the same author.

[0144] The population is defined by the degree of deviations ΔS_(m) forthe similar signatures of the same person.

[0145] 100(=10×10) sample points are defined in the signature so that100 degrees of deviations ΔS_(m) are defined as samples. A samplevariance of the degrees of deviation of 100 samples is calculated. It isassumed that the sample variance is 0.121. The past variance for thatpopulation is assumed to be 0.1 (which is read out from the referencevalue storage section 4). The test is to determine whether or not thevariance 0.121 is larger than the past variance 0.1 with the significantlevel of 1%.

[0146] (i) H₀ (null hypothesis): σ²=0.1.

[0147] (ii) H₁ (alternative hypothesis): σ²>0.1.

[0148] The critical value of σ² is calculated based on the past variance(0.1), χ²0.01(99), and the number of samples (100) as follows:$\begin{matrix}{\quad {0.1 + {\chi^{2}0.01{(99)/\left( {100 - 1} \right)}}}} \\{= \quad {0.1 + {134.63/99}}} \\{= \quad 0.136}\end{matrix}$

[0149] Since the present sample variance 0.121 is not larger than thecritical value 0.136, null hypothesis H₀ is not rejected. Therefore, itcannot be said that the degree of deviation is not the degree ofdeviation of two different but similar signatures of the same author.

[0150] Now, computation and identification of the degree of deviation ina color will be described.

[0151] The color of a signature can be digitized in a color space. Thecolor spaces include an RGB color space, a CMY(K) color space, an HSLcolor space or the like. Hereinafter, a description will be given byusing a numeric representation of colors in the RGB color space and HSLcolor space. In the RGB color space, the colors can be numericallyexpressed with three colors R (red), G (green), and B (blue). Comparingsignature “A” and signature “B” denotes comparing a color obtained whenthe result obtained by projecting signature “A” onto the two-dimensionalplane is projected onto a pixel plane with a color obtained when theresult obtained by projecting signature “B” onto the two-dimensionalplane is projected onto a pixel plane.

[0152]FIG. 5 is a flowchart of an identity judgment procedure based onthe colors of signature “A” and signature “B”. Although steps S7100 toS7150 are performed at the collation section 3, steps S7100 to S7140 maybe performed at the stage of generating digital data. Step S7160 isperformed at the hypothesis test section 5.

[0153] At step S7100, signature “A” or signature “B” is enlarged orreduced, thereby making signature “A” and signature “B” comparable byusing a method for equalizing the widths or heights of signature “A” andsignature “B” or the widths and heights of the signatures “A” and “B”,or, products of the widths and heights thereof.

[0154] At step S7110, a frame of a rectangle is generated on a pixelplane, and the frame of the rectangle is divided into L square orrectangle lattices.

[0155] At step S7120, when signature “A” and signature “B” are appliedto the frame of the rectangle, numbers 1, 2, 3, . . . M are assigned toeach lattice in which even one pixel on signature “A” or signature “B”exist.

[0156] At step S7140, the colors in a pixel can be numerically expressedwith three colors of R (red), G (green), and B (blue). The number ofpixels on each lattice m(m=1, 2, 3, . . . M) is defined as N, andnumbers mn are assigned to pixels of lattice m(m=1, 2, 3, . . . M).

[0157] The colors of a pixel mn is represented by a red numeric valueR_(mn), green numeric value G_(mn), and blue numeric value B_(mn). Thecolors of a lattice m(m=1, . . . M) are represented by the formulabelow.${R_{m} = \frac{\sum\limits_{n = 1}^{N}R_{n\quad m}}{N}},{G_{m} = \frac{\sum\limits_{n = 1}^{N}G_{n\quad m}}{N}},{B_{m} = \frac{\sum\limits_{n = 1}^{N}B_{n\quad m}}{N}}$

[0158] Although the colors of m′n′ other than signatures can be usedintact, they may be defined as R_(m′m′)=G_(m′n′)=B_(m′n′)=K (constant),where the constant K is mainly used as “0”, a “possible minimum value”,a “possible maximum value”, a “possible intermediate value”, or a “valuerepresenting a gray at a reflection index of about 18%”.

[0159] The colors of signature “A” on lattice m(m=1, 2, 3, . . . M) aredefined as R_(Am), G_(Am), and B_(Am)(m=1, 2, 3, . . . M), and thecolors of signature “B” on lattice m(m=1, 2, 3, . . . M) are defined asR_(Bm), G_(Bm), and B_(Bm)(m=1, 2, 3, . . . M).

[0160] At step S7150, the degrees of deviation in colors of signature“A” and signature “B” on lattice m(m=1, 2, 3, . . . M) are obtained asfollows:

ΔR_(m)=R_(Bm)−R_(Am),

ΔG_(m)=G_(Bm)−G_(Am),

ΔB_(m)=B_(Bm)−B_(Am)

[0161] At step S7160, a test of hypothesis is performed as follows.

[0162] (1) The population is defined by the degree of deviation ΔR_(m)in the R value of the RGB color model for the same signature under thedifferent projection conditions J_(A) and J_(B). It is assumed that thepopulation follows the normal distribution. The value of R is rangingfrom 0 to 255.

[0163] (i) Without preliminary compensation for color value

[0164] In the past experiences, it is known that the red value becomeslarge due to the color deviation of the lens under the projectionconditions J_(B). The past mean and variance are −10 and 2 (which areread out from the reference value storage section 4). 100(=10×10) samplepoints are defined in the signature so that 100 degrees of deviationsare defined as samples. A sample variance is calculated. It is assumedthat the sample variance is 3 with the mean −10 being known. The test isto determine whether or not the sample variance 3 is significantlylarger than the past variance 2 with the significant level of 1%.

[0165] (a) H₀ (null hypothesis): σ²=2.

[0166] (b) H₁ (alternative hypothesis): σ²>2.

[0167] The critical value of σ² is calculated based on the past variance(2), χ²0.01(100) (which is a value of a significant level of 1% under χ²distribution of 100 degrees of freedom), and the number of samples (100)as follows: $\begin{matrix}{{2 \times x^{2}0.01{(100)/100}} = {2 \times {135.8/100}}} \\{= 2.7}\end{matrix}\quad$

[0168] Since the present variance 3 is larger than the critical value2.7, null hypothesis H₀ is rejected. Therefore, it cannot be said thatthe degree of deviation is based on the projection.

[0169] (ii) With preliminary compensation for color value

[0170] In the past experiences, it is known that the red value becomeslarge due to a lower color temperature under the projection conditionsJ_(B). The red value can be compensated for as follows.

R _(Bm)′=(R _(Bm)/255)^(1.5)×255

[0171] After the red values R_(Bm) are amended to R_(Bm)′, the test canbe performed on the assumption that the projection conditions J_(A) andJ_(B) are identical to each other.

[0172] (2) The population is defined by an absolute value of the degreeof deviation |ΔR_(m)| in the R value of the RGB color model for the samesignature under the different projection conditions J_(A) and J_(B). Itdoes not matter whether or not the population follows the normaldistribution.

[0173] In the past experiences, it is known that the red value becomeslarge due to the color deviation of the lens under the projectionconditions J_(B). The red value can be compensated for as follows.

R _(Bm)′=(R _(Bm)/255)^(1.5)×255

[0174] After the red values R_(Bm) are amended to R_(Bm)′, the test canbe performed on the assumption that the projection conditions J_(A) andJ_(B) are identical to each other. 100(=10×10) sample points are definedin the signature so that 100 degrees of deviations are defined assamples. A sample mean is calculated. It is assumed that the sample meanis 0.12. The past mean and variance for that population are assumed tobe 0.1 and 1 (which are read out from the reference value storagesection 4). The test is to determine whether or not the present samplemean 0.12 is larger than the past mean 0.1 with the significant level of1%.

[0175] (a) H₀ (null hypothesis): μ=0.1.

[0176] (b) H₁ (alternative hypothesis): μ>0.1.

[0177] The critical value of μ is calculated based on the past mean(0.1), z(0.01), and the number of samples (100) as follows:$\begin{matrix}{{0.1 + {{z(0.01)} \times \left( {1/100} \right)^{1/2}}} = {0.1 + {0.496 \times 0.1}}} \\{= 0.1496}\end{matrix}\quad$

[0178] Since the present mean 0.12 is not larger than the critical value0.1796, null hypothesis H₀ is not rejected. Therefore, it cannot be saidthat the degree of deviation is not based on the projection.

[0179] (3) The population is defined by an absolute value of the degreeof deviation |ΔS_(m)| in the S value of the HSL color model (H (hue), S(saturation), and L (lightness)) for the same signature under thedifferent projection conditions J_(A) and J_(B). The S value is rangingfrom 0 to 100.

[0180] In the past experiences, it is known that the S value becomessmall due to 100-year aging under the projection conditions J_(B). The Svalue can be compensated for as follows.

S _(Am)′=min{0, S _(Am)−10 }

[0181] After the S values S_(Am) are amended to S_(Am)′, the test can beperformed on the assumption that the projection conditions J_(A) andJ_(B) are identical to each other.

[0182] 100(=10×10) sample points are defined in the signature so that100 degrees of deviations are defined as samples. A sample mean iscalculated. It is assumed that the sample mean is 0.12 and the samplevariance is 1. The past mean for that population is assumed to be 0.1(which is read out from the reference value storage section 4). The testis to determine whether or not the present sample mean 0.12 is largerthan the past mean 0.1 with the significant level of 1%.

[0183] (a) H₀ (null hypothesis): μ=0.1.

[0184] (b) H₁ (alternative hypothesis): μ>0.1.

[0185] The critical value of μ is calculated based on the past mean(0.1), z(0.01), sample variance(1) and the number of samples (100) asfollows: $\begin{matrix}{{0.1 + {{z(0.01)} \times \left( {1/100} \right)^{1/2}}} = {0.1 + {0.496 \times 0.1}}} \\{= 0.1496}\end{matrix}\quad$

[0186] Since the present mean 0.12 is not larger than the critical value0.1496, null hypothesis H₀ is not rejected. Therefore, it cannot be saidthat the degree of deviation is not based on the projection.

[0187]FIG. 5 shows the identity determination. Another example forsearching for the similar work will be described.

[0188] (1) H₀ (null hypothesis): It is assumed that the degree ofdeviation is due to the different (but similar) signatures of the sameauthor.

[0189] (2) H₁ (alternative hypothesis): It is assumed that the degree ofdeviation is significantly larger than the degree of deviation due tothe different (but similar) signatures of the same author.

[0190] The population is defined by the degree of deviations ΔS_(m) forthe similar signatures of the same person.

[0191] 100(=10×10) sample points are defined in the signature so that100 degrees of deviations ΔS_(m) are defined as samples. A samplevariance of the degrees of deviation of 100 samples is calculated. It isassumed that the sample variance is 0.121. The past variance for thatpopulation is assumed to be 0.1 (which is read out from the referencevalue storage section 4). The test is to determine whether or not thevariance 0.121 is larger than the past variance 0.1 with the significantlevel of 1%.

[0192] (i) H₀ (null hypothesis): σ²=0.1.

[0193] (ii) H₁ (alternative hypothesis): σ²>0.1.

[0194] The critical value of σ² is calculated based on the past variance(0.1), χ²0.01(99), and the number of samples (100) as follows:$\begin{matrix}{{0.1 + {x^{2}0.01{(99)/\left( {100 - 1} \right)}}} = {0.1 + {134.63/99}}} \\{= 0.136}\end{matrix}\quad$

[0195] Since the present sample variance 0.121 is not larger than thecritical value 0.136, null hypothesis H₀ is not rejected. Therefore, itcannot be said that the degree of deviation is not the degree ofdeviation of two different but similar signatures of the same author.

[0196] In the present embodiment, the precision of judgment can beincreased by properly combining these judgments without being limited tosingle judgments of the above described shape, area, and color.

[0197] The present embodiment is applicable in any of the cases below.

[0198] (1) Work identification by judging identity of a signature

[0199] The uniqueness or originality of a work is characterized in thatit can be verified by the signature, of which there is only one. Thesignature of work “A” is registered in advance as a result of projectiononto a two-dimensional plane, and the signature of work “B” is examinedwith the result of the projection into the two-dimensional planerelevant to the shape, area, and color, thereby making it possible toelectronically judge whether or not the work “A” and the work “B” areidentical to each other.

[0200] (2) Work identification by judging identity of shape

[0201] A work is characterized by the form of its surface, representedby depressions, thus usable in verification of its creator. Work “A” isregistered in advance as a result of projection onto a two-dimensionalplane, and work “B” is examined with the result of projection onto thetwo-dimensional plane relevant to the shape, area, and color, therebymaking it possible to electronically judge whether or not the work “A”and the work “B” are identical to each other.

[0202] In addition, a plurality of cross sections of a depression areprojected onto the two-dimensional plane, thereby making it possible toobtain a closed curve that represents the shape of the depression foreach cross section. As in the above embodiment, the works are examinedrelevant to the shape and area, thereby making it possible toelectronically judge whether or not the work “A” and the work “B” areidentical to each other.

[0203] Parametric spline interpolation used in the above embodiment isapplicable to a three-dimensional space as in the two-dimensional space.Work “A” is registered in advance as a result of projection onto athree-dimensional plane, and work “B” is examined with the result ofprojection onto the three-dimensional plane relevant to the shape, area,and color, thereby making it possible to electronically judge whether ornot the work “A” and the work “B” are identical to each other.

[0204] (3) Work identification by judging the identity of pictures andphotographs

[0205] In most cases, the works of pictures or photographs arerectangular in shape, thus making it difficult to characterize, by itsshape or area, that the work is the only one work. However, it ischaracterized by the distribution of colors as to whether or not thatwork is only one. Work “A” is registered in advance as a result ofprojection onto a two-dimensional plane, and work “B” is examined withthe result of projection onto the two-dimensional plane relevant to thecolor, thereby making it possible to electronically judge whether or notthe work “A” and the work “B” are identical to each other.

[0206] (4) Searching the author's name from an image of the work

[0207] The correlation of identity is performed by using the projectionresult of an unspecified number of works registered in advance and theresult of projection of a work whose author's name is to be searched,thereby a similar work can be searched. This enables to search bydefining an image itself as a key instead of search by defining acharacter string as a key.

[0208] A work identity judgment system according to the presentembodiment comprises a storage section which stores digital data on onlyone work; a target storage section which stores digital data on a workto be identified; a collation section which collates digital data storedin the storage section and the target storage section to obtain a degreeof deviation; a reference value storage section which stores referencevalues for test of hypothesis; and a test section which performs test ofhypothesis based on the degree of deviation and the reference value. Thedigital data is the projection result of only one work and a work to beidentified. The degree of deviation is calculated by defining theprojection result as function data in the shape in a plurality ofregions. The test of hypothesis is performed to determine whether thedegree of deviation is based on the projection condition or is thedegree of deviation of two different signatures, thereby judging theidentity of the work. Further, it is possible to search for a similarwork if the work to be identified is compared with plural only oneworks. The shape of the signature or the work is stored as digital data,and the difference is digitized, thereby making it possible toelectronically judge the identity of the work.

[0209] The degree of deviation can be calculated by defining the digitaldata as color data in a plurality of regions, whereby the judgment ofidentity of work can be performed based on color.

[0210] The degree of deviation can be calculated by defining the digitaldata as area data in a plurality of regions, whereby the judgment ofidentity of work can be performed based on area.

[0211] It is possible to freely select at least one of the degrees ofdeviation in the shape, area, and color depending on the type of thework to be identified.

[0212] A reference value (significant level for critical region) isselected for the degree of deviation in color in consideration of colorfading or change of color, whereby the judgment of identity of a workcan be performed more precisely.

[0213] Identification can be performed as long there is only one work,the work being characterized by its shape, color, or area or acombination thereof.

[0214] In addition, when there exists an unspecified number of Nsignatures “A1”, . . . “AN” and one signature “B”, the degree ofdeviation in each of the shape, area, and color of the signatures “Ai”(i=1, . . . M) and “B” is obtained, and test of hypothesis is performedN times, whereby a signature similar to “B” can be searched from among“Ai” (i=1 . . . N).

[0215] Other embodiments of the present invention will be described. Inthe following embodiments, like elements corresponding to those in thefirst embodiment are designated by the same reference numbers and thedetailed description thereof is omitted.

Second Embodiment

[0216] When an author or owner approves use of one's digitized work bythe other person, the author or owner may approve it by includingsignature insertion.

[0217] A digitized signature is stored in a signature database, whereby,if the author or owner approves use of such a digitized work, thesignature can be electronically inserted into a work, e.g., through anelectronic network, and the signed work can be distributed, e.g.,through an electronic network, making it possible to prevent use of adigitized work into which no signature is inserted.

[0218] For example, assume that one photographer does not want to inserthis or her signature into a negative or positive film that is anoriginal of a work, but wants to insert his or her signature when thatwork is used for advertisement. Assume that the photographer's signatureis produced as digital data, the signature is stored in a signaturestorage section, and a work is digitized, and is stored in a workstorage section. When one advertisement company searches for a digitizedwork stored in the work storage section through an electronic network,such as Internet, a decision was made to use the photographer's work.When the advertisement company specifies a signature insertion positionat a lower right so as not to compete with the layout of anadvertisement statement, a digitized work into which the photographer'ssignature is inserted at the lower right by means of a signatureinsertion section is distributed to the advertisement company.

[0219] In addition, when the author or owner approves use of thedigitized work, he or she may approve it including insertion of asignature into a position of the signature in harmony with the work,specified by the author or owner.

[0220] When a digitized signature is stored in the signature storagesection or when a digitized work is stored in the signature storagesection, the insertion position of the signature approved in advance aswell is stored, whereby the signature position desired by the author,owner or user can be electronically determined, thus making it possibleto prevent from inserting a signature into a digitized work at aposition that is not desired by the author or owner.

[0221] For example, assume that a photographer had determined that awork and a signature are most harmonized when the signature is insertedat the bottom right from the center of the work. When the digitized workis stored in the work storage section, four possible signature insertionpositions are stored. An advertisement company who wants to use a workcan select a signature position that is not competed with the layout ofan advertisement statement from such four signature positions.

[0222] Alternately, when an author or owner approves use of a digitizedwork, the author or owner may approve it including use of the work forthe purpose of use suitable to the work, which is specified by theauthor or owner. When the digitized signature is stored in the signaturestorage section or when the digitized work is stored in the signaturestorage section, the purpose of use of the work approved in advance aswell is stored, whereby the purpose of use of the work desired by theauthor, owner, and user can be electronically determined, thus making itpossible to prevent use of the work for a purpose that is not desired bythe author or owner.

[0223] For example, assume that a photographer wants to approve only usefor academic purpose. When a digitized work is stored in the workstorage section, an academic purpose as well is stored as a purpose ofuse of a work approved in advance. A publishing company who wants to usethe work attempts to use it for production of educational matters, andcan use the photographer's work.

[0224] When the digitized work is used for printing, advertisement,publishing, homepage, distribution, sales, exhibition, computer softwareinstallation or the like, the digitized signature is electronicallyinserted in the digitized work, whereby an unspecified number of workauthors and an unspecified number of users can insert their signaturesinto the work, approve use of the work, and distribute the work inconsideration of their desires.

[0225] In a work, one wants to specify the author or owner of the workfrom the signature of the work or work itself.

[0226] By storing a digitized signature in the signature storage sectionor by storing a digitized work in the work storage section, when theauthor or owner is unknown by referring to the work or signature, theauthor's name or owner's name can be searched from the digitizedsignature or digitized work by the signature search section or the worksearch section.

[0227] For example, assume that a landscape photograph is used for aposter. If that photograph has an author's signature, and the signatureis stored in the signature storage section, when a person who likes thatwork by referring to it digitizes a signature portion by means of ascanner, and transmits it to the signature search section through theInternet, the name of the photographer using that signature istransmitted as a result of the search. The author of the desired workcan be known by electronically searching for the author of the work.

[0228] In addition, assume that an oil painting is used in publishingmatter. If a museum's signature is inserted into that work, and themuseum's signature is stored in the signature storage section, when aperson who likes the work by referring to it digitizes a signatureportion by means of a scanner, and transmits it to the signature searchsection through the Internet, the name of the museum using thatsignature is transmitted as a result of search. The owner of the work iselectronically searched, whereby the person can know the museum thatowns the work in order to actually appreciate the work.

[0229] The author or owner of the work is electronically specified,whereby appreciation of works such as pictures or photographs can beeasily made popular.

[0230] One wants to identify the author of a work.

[0231] A signature that is a part of the work is digitized and stored inthe signature storage section or a digitized work is stored in the workstorage section, whereby, when an attempt is made to identify the authorof the work, the author can be electronically identified from thesignature or work by means of a signature identification section or awork identification section.

[0232] For example, assume that a famous painter's oil painting has beenintroduced in an auction. Assume that the painter stored his or hersignature in the signature storage section when the work was produced.Although the painter died 200 years ago and it is difficult to identifywhether or not the introduced work is the painter's work, when anauction company photographs the signature of the work by means of adigital camera, and transmits it to the signature identification sectionthrough the Internet, the result of the identification electronicallyperformed is transmitted.

[0233] When it is necessary to identify the author of the work bytrading, leasing, donation, exchange or the like, represented byauction, if a digitized signature is stored in the signature storagesection, the signature of the work to be identified is electronicallycompared with the signature stored in the signature storage section,thereby making it possible to precisely judge the author of the work.

[0234] Now, the terms used in the present embodiment will be describedhere.

[0235] Work: A work is produced by an author, and is associated withonly one work when no identical works exist. The works includepaintings, photographs, block prints, pasted pictures, sculptures,statues, pots, earthenware, and calligraphy or the like.

[0236] Projection: Converting information on one space to information onanother space. For example, projecting an object in a three-dimensionalspace by an analogue camera denotes projecting into a two-dimensionalplane on a film. Projecting an object in a three-dimensional space by adigital camera or scanner denotes projecting into a pixel plane that isa two-dimensional plane. Projecting a cross section of an object in athree-dimensional space denotes projecting into a two-dimensional plane.Projecting into a three-dimensional space is possible by projecting thecross section of an object in a three-dimensional space a plurality oftimes. An object in a three-dimensional space is projected at a varietyof angles, thereby enabling to project into the three-dimensional space.Expressing an object in a three-dimensional space as a two-dimensionalfunction denotes projecting into a two-dimensional plane. Expressing anobject in a three-dimensional space denotes projecting into athree-dimensional space. Expressing data in the two-dimensional pixelplane as a two-dimensional function denotes projecting into atwo-dimensional plane.

[0237] Digital Data: Digitized information. Images in a pixel plane,points, functions or the like in a two-dimensional plane areexemplified, but not limited thereto, and information expressed by acombination of numerals can be employed.

[0238] Electronic Work: An electronic work is directed to a workconverted into digital data by projecting a work. A work produced byusing graphic software or the like originally corresponds to digitaldata and an electronic work. A work in which an electronic work isprojected to be converted into digital data corresponds to an electronicwork. When an electronic work is stored in the work storage section, theuse of a work into which a signature is inserted can be approved by anunspecified number of customers, thereby making it possible to identifyan author by electronically judging the identity of a work using thework identification section or to specify an author by electronic searchfor a work using the work search section.

[0239] Signature: A signature in a work such as picture or photograph isa set of closed curves instead of a combination of open curves, and hasa shape, an area, and a color in a portion enclosed in the closedcurves.

[0240] Customer (user, searcher, or identification requester): Acustomer is directed to a user who uses an electronic work for printing,advertisement, publishing, homepage, distribution, sales, exhibition,computer software installation or the like, a searcher who wants tospecify an author or owner from signature or work, or an identificationrequester who requests identification when it is necessary to identifythe author of the work by trading, leasing, donation, exchange or thelike, by auction.

[0241] Independent Signature: This signature is independent of a work,and is defined as an independent signature to be inserted into anelectronic work without being inserted into the work itself. Mainly,this signature is of an individual that is the author or an organizationsuch as museum, picture gallery, company that is the owner.

[0242] Electronic Independent Signature: This signature is provided byprojecting an independent signature, thereby converting it into digitaldata. Alternatively, this signature is directed to an independentsignature produced as digital data in advance. In the case where anauthor or owner wants to insert an independent signature into a workwhen an electronic work is used for printing, advertisement, publishing,homepages, distribution, sales, exhibition, computer softwareinstallation or the like, the electronic independent signature is storedin the independent signature storage section so that the electronic workinto which the electronic independent signature is inserted by thesignature insertion section can be distributed to a user. This makes itpossible to specify an author or owner through electronic search usingthe signature search section or to identify the author by electronicallyjudging the identity of signature using the signature identificationsection.

[0243] Signature Position: This position denotes a position at which anelectronic independent signature on an electronic work is inserted whenthe electronic independent signature is inserted into an electronicwork. An electronic independent signature is independent of anelectronic work, and thus, the electronic independent signature can beinserted at a preferred position when the electronic work is used. Theauthor or owner approves the signature position. A signature positionapproval section electronically performs approval.

[0244] Work Use Purpose: A purpose of use of an electronic work. The usepurpose of a work is approved by an author or owner. A work use purposeapproval section electronically performs approval.

[0245] Specific Signature: A signature to be inserted into a work by anauthor by overwriting, engraving, pasting, embedding, burning, anddissolving or the like is defined as a specific signature. This specificsignature corresponds to a work one by one. If a work is by the sameperson, such a work exists in the form of only one work in which thesame signature does not exist. Thus, this specific signature can be usedto judge the identity of only one work. Although a painter often insertsa date and an author's signature when he or she completes oil painting,this is an example of specific signature. In the case of photographs,there are many works in which such a specific signature is notperformed.

[0246] Electronic Specific Signature: This signature is provided byprojecting a specific signature, thereby converting it into digitaldata. The electronic specific signature is stored in the specificsignature storage section, thereby making it possible to identify anauthor by electronically judging the identity of a signature using thesignature identification section or to specify an author by anelectronic search for a signature using the signature search section.

[0247] Electronic Network: An electronic network mainly denotes theInternet. In addition to the Internet, this network includes a wired orwireless information transmission section such as LAN, WAN, wirelessLAN, an information transmission medium such as hard disk, memory,floppy disk, CD, MO, IC card or the like, and a digital data informationtransmission section including an information transmission section suchas a signal transfer path, represented by a bus generally installedbetween computer hardware components.

[0248] Signature storage Section, Work Storage Section: A signaturestorage section and a work storage section store signature and workdigital data by utilizing computer hardware or software. For example,when a hard disk or CD, memory, or IC card is used, an electronicsignature or electronic work can be stored.

[0249] Electronic Signature storage Company: This company has anelectronic signature management system capable of storing an electronicsignature, electronically inserting a signature into a work,distributing an electronically signed electronic work, electronicallyapproving use of the work, and electronically specifying an author orowner of the work.

[0250] Hereinafter, a second embodiment of the present invention will bedescribed in detail.

[0251]FIG. 6 is a block diagram depicting a basic configuration of awork signature management system according to the present invention. Awork 101 produced by an author is defined as a digitized electronic work101 a. In addition, a specific signature extracted from a part of thework is defined as a digitized electronic specific signature 101 b. Theformer is stored in a work storage section 102 including a storagedevice. The latter is stored in a specific signature storage section 104including a storage device. On the other hand, an independent signatureproduced by an author or owner is defined as an electronic independentsignature 101 c, and is stored in an independent signature storagesection 103 including a storage device. A signature storage section 105includes the independent signature storage section 103 and specificsignature storage section 104.

[0252] A signature insertion section 106 generally composed of computerhardware and software includes a signature position approval section 107and a work use purpose approval section 108. An electronic independentsignature received from the independent signature storage section 103 isinserted into a properly approved position on an electronic workreceived from the work storage section 102 by approval of the work usepurpose approval section 108 and by approval of the signature positionapproval section 107.

[0253] A signature/work search section 109 generally composed ofcomputer hardware and software basically operates as a signature searchsection and a work search section. The signature search section searchesfor a similar signature from the electronic signatures stored in theindependent signature storage section 103 and specific signature storagesection 104. The work search section searches for a similar work fromthe electronic works stored in the work storage section 102.

[0254] A signature/work identification section 111 generally composed ofcomputer hardware and software basically operates a signatureidentification section and a work identification section. The signatureidentification section compares digital data on signatures stored in theindependent signature storage section 103 and specific signature storagesection 104 with digital data on a signature to be identified, therebyjudging the identity. The work identification section compares anelectronic work stored in the work storage section 102 with anelectronic work to be identified, thereby judging the identity.

[0255] These work storage section 102, independent signature storagesection 103, and specific signature storage section 104 are indirectlyconnected to a customer's electronic system 120 through the signatureinsertion section 106, signature/work search section 109, andsignature/work identification section 111, The signature insertionsection 106, signature/work search section 109, and signature/workidentification section 111 are directly connected to the customer'selectronic system 120 through an electronic network 115 such as theInternet. In this manner, the result is transmitted through theelectronic network 115 according to the customer's order through theelectronic network 115.

[0256] The arrow of FIG. 6 indicates information transmission. Inaddition, in this example, the area above the dotted line denotes anelectronic signature storage company's system.

[0257] The signature/work search section 109 comprises a storage section109 a which stores data from the work storage section 102, independentsignature storage section 103, and specific signature storage section104; a storage section 109 b which stores digital data or condition dataon a signature or work sent from a customer; a search section 109 cwhich makes search based on the digital data or condition data on thesesignatures or works; and a result output section 109 d which outputs thesearch result.

[0258] The signature/work identification section 111 comprises a storagesection 111 a which stores digital data from the work storage section102, independent signature storage section 103, and specific signaturestorage section 104; a storage section 111 b which stores digital dataon a signature/work to be identified, sent from a customer; a comparisonsection 111 c which compares these data; and a result output section 111e which outputs the identification result. Although only essential partsof the signature/work identification section 111 have been described,this section may be identical to that of the work identification systemaccording to the first embodiment shown in FIG. 1.

[0259] Now, the storage steps will be described in accordance with aflowchart of the signature/work storage steps shown in FIG. 7A to FIG.7C. FIG. 7A is a flowchart showing the electronic independent signaturestorage steps; FIG. 7B is a flowchart showing the electronic specificsignature storage steps; and FIG. 7C is a flowchart showing theelectronic work storage steps.

[0260] At step S1140 shown in FIG. 7A, when an electronic work 101 a isdistributed through the electronic network 115, in the case where asignature position on the electronic work 101 a is determined, and anelectronic independent signature 101 c is inserted into the signatureposition or in the case where an attempt is made to search or identifyan author or owner from the electronic independent signature 101 c theelectronic independent signature 101 is provided.

[0261] At step S1150, the electronic independent signature 101 c isstored in the independent signature storage section 103. In this manner,when an electronic work 101 a is distributed through the electronicnetwork 115, the signature position on the electronic work 101 a isdetermined, whereby an electronic work into which the electronicindependent signature 101 c is inserted at the signature position can bedistributed, thus making it possible to prevent an electronic work intowhich no electronic independent signature 101 c is inserted from beingused. In addition, when a searcher searches the electronic independentsignature 101 c, information on author's name is obtained. In addition,when an identification requester makes a request for identification ofan independent signature, the identity can be collated precisely.

[0262] At step S1160, when the electronic independent signature 101 c isstored in the independent signature storage section 103, even in thecase where the electronic work 101 a is not stored in the work storagesection 102, some signature positions or work use purposes can be storedwith prior approval common to all the electronic works 101 a in order tospecify a signature position or a work use purpose. In addition, anapproval for use of the electronic work 101 a can be done through theelectronic network 115 including a signature position or work usepurpose.

[0263] At step S1190 shown in FIG. 7B, in the case where an attempt ismade to precisely identify an author by a signature or in the case wherean attempt is made to search or identify an author, an electronicspecific signature is provided.

[0264] At step S1200, the electronic specific signature 101 b is storedin the specific signature storage section 104. In this manner, when theidentification requester makes a request for identification of aspecific signature through the electronic network 115, the identity ofthe specific signature can be determined precisely. In addition, whenthe searcher searches the electronic specific signature 101 b,information on the author's name or title of the work is obtained.

[0265] At step S1220 shown in FIG. 7C, in the case where the electronicwork 101 a into which the electronic independent signature 101 c isinserted is stored to distribute an unspecified number of users throughthe electronic network 115 or in the case where an attempt is made tosearch or identify an author by the electronic work 101 a, theelectronic work 101 a is provided.

[0266] At step S1230, the electronic work 101 a is stored in the workstorage section 102. In this manner, the electronic work 101 a intowhich the electronic independent signature 101 c is inserted can bedistributed through the electronic network 115. In addition, when thesearcher searches the electronic work 101 a, information on the author'sname or the like is obtained. In addition, when the identificationrequester makes a request for identification of a work, the identity canbe precisely collated.

[0267] At step S1240, when the electronic work 101 a is stored in thework storage section 102, some signature positions or work use purposesapproved in advance can be stored. In addition, an approval for use ofthe electronic work 101 a can be done through the electronic network 115including the signature position or work use purpose.

[0268] Now, steps of inserting the electronic independent signature 101c will be described in accordance with a flowchart of inserting asignature shown in FIG. 8.

[0269] At step S3110, the electronic work 101 a into which theelectronic independent signature 101 c is inserted can be selected fromone of the work stored in the work storage section 102 of an electronicsignature storage company or possessed by a user.

[0270] In the case where the electronic work 101 a stored in the workstorage section 102 of the electronic signature storage company is to beused, a target electronic work 101 a is determined at step S3120 fromamong the electronic works 101 a stored in the work storage section 102.In the case where the target electronic work 101 a is not determinedyet, the electronic work 101 a to be used is determined by making asearch. For example, in the case where an attempt is made to use aphotograph of Mt. Fuji, a search is made by defining “Mt. Fuji” as akeyword, and the electronic work 101 a for use in the search result isdetermined.

[0271] On the other hand, in the case where the electronic work 101 apossessed by a user is to be used, the user applies a signatureinsertion position or work use purpose to the electronic signaturestorage company. It is necessary for the electronic signature storagecompany before inserting the signature to confirm that the author orowner approves the signature insertion position or work use purpose. Ifthe author or owner directly passes to a user the electronic work to beused, it can be regarded that the signature position or work use purposeis approved. Therefore, it is not necessary to execute step S3160 inwhich the signature position or work use purpose is approved. However,it is not desirable to pass step S3160 only depending on the user'sapplication. Therefore, it is determined at step S3140 whether thesignature position or work use purpose is applied by the author orowner. It can be regarded that the signature position or work usepurpose applied to the electronic signature storage company was approvedby the author or owner.

[0272] If it is determined that the signature position or work usepurpose was applied to the electronic signature storage company by theauthor or owner at step S3140, the signature position approval section107 and the work use purpose approval section 108 determine at stepS3150 whether or not the author or owner approved or the approval by theuser equals to the approval by the author or owner. The determination ismade by using a general certification technique in which the author orowner is required to enter the name or password. If the certificationsucceeds, the signature position approval section 107 and the work usepurpose approval section 108 approve the signature position or the workuse purpose.

[0273] If it is determined that the signature position or work usepurpose was not applied to the electronic signature storage company bythe author or owner at step S3140, an electronic work stored in the workstorage section 102 and of the same author or having high qualitycontents is searched for at step S3145.

[0274] When the electronic work 101 a is specified at step S3120 orS3145, it is determined at step S3160 whether the user accepts thepredetermined signature insertion position and the work use purposewhich are stored in correspondence with the electronic independencesignature 101 c or the electronic work 101 a. If the user does notaccept the predetermined signature insertion position and the work usepurpose, the user applies at step S3170 a desired signature insertionposition and work use purpose to the author or owner. At step S3180, itis determined whether the author or owner approves the applied signatureinsertion position and work use purpose.

[0275] In the case where it is determined to be approved at step S3180,where it is determined that the user accepts the predetermined signatureinsertion position and the work use purpose at step S3160, or where theapproval by the author or owner is obtained at step S3150, it isdetermined at step S3181 whether an electronic work into which theelectronic independent signature 101 c is inserted is the electronicwork 101 a of the electronic signature storage company or is anelectronic work possessed by the user.

[0276] In the case of using an electronic work possessed by the user,the electronic signature storage company receives the electronic workfrom the user at step S3185, and temporary stores it in the work storagesection 102. If the electronic work 101 a is registered into the workstorage section 102, the company stores it in the work storage section102 in accordance with the storage steps (refer to FIG. 7C).

[0277] At step S3190, the electronic independent signature 101 c isextracted from the independent signature storage section 103.

[0278] At step S3200, the electronic independent signature 101 c isinserted into an approved signature position of the electronic work 101a extracted from the work storage section 102 by means of the signatureinsertion section 106.

[0279] At step S3210, the electronic independent signature 101 c isinserted into an approved signature position, and the electronic work101 a whose work use purpose is approved is transmitted to a userthrough the electronic network 115.

[0280] In actual practice, the author or owner determines four signaturepositions and determines a work use purpose that is approved or a workuse purpose that is not approved (refer to steps S1160 and S1240).

[0281] The user searches the electronic work 101 a by this system thoughthe Internet (refer to step S3120), selects a signature position that isnot competed with the character layout, checks that the work use purposeis proper (refer to step S3160), and transmits the signature positionand work use purpose to the signature insertion section 106 by selectingand describing them. Then, the signature position and work use purposeare approved (refer to step S3160), and a signature is inserted into awork (refer to steps S3190 and S3200). Here, the user can download thework (refer to step S3120). If an attempt is made to use anothersignature position or another work use purpose, the electronic signaturestorage company requests the author or owner for approval through theelectronic network 115, facsimile or the like and for determiningwhether or not to approve use of the electronic work 101 a (refer tosteps S3170 and S3180).

[0282] Now, the signature or work search steps will be described inaccordance with a flowchart of the signature/work search steps shown inFIGS. 9A and 9B. FIG. 9A is a flowchart showing the electronic signaturesearch steps; and FIG. 9B is a flowchart showing the search steps of theelectronic work 101 a.

[0283] At step S4110 shown in FIG. 9A, the user digitizes a signature ofa desired work, and transmits it to the electronic signature storagecompany through the electronic network 115.

[0284] At step S4140, the user searches an electronic signature storedin the independent signature storage section 103 or specific signaturestorage section 104 by means of the signature/work storage section 109.

[0285] At step S4150, information on author's name associated withsimilar signature or the like from the search result is transmitted tothe user through the electronic network 115.

[0286] At step S4190 shown in FIG. 9B, the user digitizes a desiredwork, and transmits it to the electronic signature storage companythrough the electronic network 115.

[0287] At step S4200, an electronic signature stored in the signaturestorage section 105 is searched by the signature/work search section109.

[0288] At step S4210, information on the author's name associated with asimilar work or the like from the search result is transmitted to theuser through the electronic network 115.

[0289] Now, the signature or work identity judgment steps will bedescribed in accordance with a flowchart of the signature/work identityjudgment steps shown in FIG. 10A and FIG. 10B. FIG. 10A is a flowchartshowing the signature identity judgment steps; and FIG. 10B is aflowchart sowing the work identity judgment steps.

[0290] At step S5110 shown in FIG. 10A, the user digitizes a specificsignature of a desired work, and transmits it to the electronicsignature storage company through the electronic network 115.

[0291] At step S5120, it is determined by a signature identificationsection 111 as to the identity between the electronic specific signature101 b stored in the specific signature storage section 104 and anelectronic signature transmitted from an identification requester,thereby identifying an author.

[0292] At step S5130, the identification result is transmitted to theuser through the electronic network 115.

[0293] At step S5140 shown in FIG. 10B, the user digitizes desired onlyone work, and transmits it to the electronic signature storage companythrough the electronic network 115.

[0294] At step S5150, the identity between the electronic work 101 astored in the work storage section 102 and an electronic worktransmitted from the identification requester is determined by a workidentification section 111, to thereby identify an author.

[0295] At step S5160, the identification result is transmitted to theuser through the electronic network 115.

[0296] Hereinafter, an example of application according to the presentinvention will be described.

[0297] (a) Approval for using an electronic work to a user when anelectronic work is already stored:

[0298] An electronic signature storage company stores an author's orowner's electronic independent signature 101 c and the electronic work101 a. A user searches for a desired electronic work 101 a (refer tosteps S3110 and S3120 ). At step S3160, the user applies the work usepurpose to the electronic signature storage company and the user judgeswhether or not the predetermined signature insertion position and thework use purpose is accepted. It is not accepted, the user applies adesired signature insertion position and work use purpose to the companyat step S3170. At step S3180, it is determined whether the author orowner approves the user-desired signature insertion position and workuse purpose. If an affirmative decision is obtained in step S3160 orS3180, an affirmative decision is also obtained in step S3181.

[0299] The electronic independent signature 101 c is extracted from theindependent signature storage section 103 at step S3190. The electronicindependent signature 101 c is inserted into an approved signatureposition of the electronic work 101 a extracted from the work storagesection 102 by means of the signature insertion section 106 at stepS3200. The electronic independent signature 101 c is inserted into anapproved signature position, and the electronic work 101 a whose workuse purpose is approved is transmitted to a user through the electronicnetwork 115 at step S3210.

[0300] (b) Approval for using an electronic work to a user when noelectronic work is stored:

[0301] An electronic signature storage company stores an author's orowner's electronic independent signature 101 c. The author or ownerdirectly gives approval for use to a user, and the user requests theelectronic signature storage company to insert a signature (refer tosteps S3110 and S3140). Since the user possesses the electronic work;step S3140 is executed after step S3110. In order to confirm that theauthor or owner approves the signature insertion position and work usepurpose, the user enters the name and the password at step S3150. If theuser is certified, a negative decision is obtained in step S3181 and theelectronic work transmitted from the user is stored in the storagesection 102 at step S3185.

[0302] The electronic independent signature 101 c is extracted from theindependent signature storage section 103 at step S3190. The electronicindependent signature 101 c is inserted into an approved signatureposition of the electronic work 101 a extracted from the work storagesection 102 by means of the signature insertion section 106 at stepS3200. The electronic independent signature 101 c is inserted into anapproved signature position, and the electronic work 101 a whose workuse purpose is approved is transmitted to a user through the electronicnetwork 115 at step S3210.

[0303] (c) When the user wants to use an electronic work whose author isunknown, using no search parameters:

[0304] An author or owner is specified by searching an electronicsignature or electronic work as shown in FIG. 9A or FIG. 9B. In the casewhere the author or owner has been specified, if the electronic work isstored in the work storage section 102 of the electronic signaturestorage company, a processing similar to (a) is performed.

[0305] In the case where no work is stored, a negative decision is madein steps S3110 and S3140, the user applies the work use purpose to theelectronic signature storage company and the user judges whether or notthe predetermined signature insertion position and the work use purposeis accepted at step S3160. It is not accepted, the user applies adesired signature insertion position and work use purpose to the companyat step S3170. At step S3180, it is determined whether the author orowner approves the user-desired signature insertion position and workuse purpose. If an affirmative decision is obtained in step S3160 orS3180, an affirmative decision is also obtained in step S3181.

[0306] The electronic independent signature 101 c is extracted from theindependent signature storage section 103 at step S3190. The electronicindependent signature 101 c is inserted into an approved signatureposition of the electronic work 101 a extracted from the work storagesection 102 by means of the signature insertion section 106 at stepS3200. The electronic independent signature 101 c is inserted into anapproved signature position, and the electronic work 101 a whose workuse purpose is approved is transmitted to a user through the electronicnetwork 115 at step S3210.

[0307] (d) Search when an electronic signature or electronic work isdefined as a search parameter:

[0308] Conventionally, a work has been searched by defining a characterstring or numeric value such as author, age, or title of the work. Inthe case where the user does not know an author or title of the workeven if he or she has an image at hand, such an author or title of thework could not be searched for. However, the author or title of the workcan be searched from an electronic signature or electronic work by usinga signature search section 109 (refer to FIG. 9A and FIG. 9B). Thus,even when the user attempts to use an electronic work, there iseliminated a case in which an approval cannot be obtained because theuser does not know the author or owner of the desired work.

[0309] (e) Identification of an author using a signature in an auction:

[0310] An electronic signature storage company (a specific signaturestorage section 104) stores a work specific signature. When an auctioncompany or the like that is a user of this system specifies an author ofa work, the user can correctly identify the author by identifyingdigital data of a signature of a work exhibited in auction and anelectronic specific signature stored in the specific signature storagesection 104 (refer to FIG. 10A and FIG. 10B).

[0311] The entire work can be identified without being limited to asignature.

[0312] According to a work electronic signature management system of thepresent embodiment, there are provided a signature storage section whichstores digitized signatures, a work storage section which storesdigitized works, and a signature insertion section which inserts asignature selected from the signature storage section into a workselected from the work storage section. There may be further provided anelectronic network for directly or indirectly connecting the signaturestorage section, work storage section, and signature insertion sectionto a customer's electronic system. The signature selected from thesignature storage section is inserted into the work selected from thework storage section by means of the signature insertion section inresponse to a request received through the electronic network, and thework is transmitted through the electronic network in response to therequest. In this manner, in distributing a digitized work, a properposition into which a digitized signature on a digitized work isinserted is determined through the electronic network, a signature isinserted into that position, and a work into which the signature isinserted is distributed to an unspecified number of customers throughthe electronic network.

[0313] There is further provided a signature judgment section whichcompares a signature stored in the signature storage section with asignature to be determined, and judges the identity. The judgmentsection is directly or indirectly connected to the electronic network.In response to a request received through the electronic network, theresult obtained by comparing the signature stored in the signaturestorage section with the signature to be determined and judging theidentity is transmitted to the requester through the electronic network,whereby the identity of the digitized signature can be preciselydetermined through the electronic network.

[0314] There is further provided a work judgment section which comparesthe work stored in the work storage section with a work to bedetermined, and judges the identity. The judgment section is directly orindirectly connected to the electronic network. In response to a requestreceived through the electronic network, the result obtained bycomparing the work stored in the work storage section with the work tobe determined and judging the identity is transmitted to the requesterthrough the electronic network, whereby the identity of the digitizedwork can be precisely determined through the electronic network.

[0315] The signature insertion section comprises a signature positionapproval section, wherein, only in the case where a signature positioncorresponds to a signature position approved in advance or a newlyapproved signature position, the signature insertion section inserts asignature into a signature position approved on a work, whereby adigital signature can be inserted into a signature position approved ona digitized work. The signature position desired by the author or ownerand the user can be electronically determined, thereby making itpossible to prevent a signature from being inserted into an author orowner undesired position.

[0316] The signature insertion section comprises a work use purposeapproval section, wherein, only in the case where a work use purposecorresponds to a work use purpose approved in advance or a newlyapproved work use purpose, the signature insertion section inserts asignature into a signature position approved on a work, whereby the usepurpose of a digitized work can be electronically approved, making itpossible for the author or owner to prevent undesired use of the work.

[0317] There is provided a signature search section which searches for asignature from a signature storage section, the signature search sectionbeing directly or indirectly connected to the electronic network,wherein, in response to a request received through the electronicnetwork, the result obtained by searching a signature from the signaturestorage section by means of the signature search section is transmittedto the requester through the electronic network, whereby a digitizedsignature can be searched through the electronic network, and the authoror owner of the work can be electronically specified from the signature.

[0318] There is provided a work search section which searches for a workfrom a work storage section, the work search section being directly orindirectly connected to the electronic network, wherein, in response toa request received through the electronic network, the result obtainedby searching a work from the work storage section by means of the worksearch section is transmitted to the requester through the electronicnetwork, whereby a digitized work can be searched through the electronicnetwork, and the author or owner of the work can be electronicallyspecified from the work.

[0319] According to the second embodiment, a signature in an individualpiece of work is one factor that specifies that work. By digitizing andstoring the signature of work “A”, when work “B” appears later, thesignature of the stored and digitized work “A” and the digitizedsignature of work “B” are compared with each other, thereby making itpossible to electronically identify whether or not the works “A” and “B”are identical to each other. The references used for identificationinclude the shape, area, and color of the signature, as described in thefirst embodiment. The degree of deviation of each of the shape, area,and color is obtained relevant to each of the signatures of the works“A” and “B”, and the test of hypothesis is performed by using the nullhypothesis and alternative hypothesis.

[0320] Any shape and object can be searched without being limited toonly one work.

[0321] As has been described above, according to the present invention,a work or signature is obtained as digital data, and the degree ofdeviation is numerically obtained, thereby making it possible toprecisely judge the identity. In addition, an electronic work identityjudgment technique is added to visual inspection, knowledge, andexperience of an expert in the field or of the creator of the work, tothereby identify the author of the work more precisely.

[0322] In the work signature management system according to the presentinvention, before a digitized work is distributed through the electronicnetwork, a proper signature insertion position on the digitized work isdetermined, and a signature is inserted into that position, whereby thework into which the signature has been inserted is distributed.

[0323] The present invention is not limited to the above describedembodiments, and various modifications can be made occur. For example,the present invention can be implemented as a computer readablerecording medium having stored therein a program causing a computer toexecute a predetermined section (or causing a computer to function as apredetermined section or achieve a predetermined function)

1. A work identification system comprising: a work storage configured tostore digital data representing at least one of a shape, area, and colorof an only one work; a collation section configured to calculate adegree of deviation between digital data representing at least one of ashape, area, and color of a target work to be identified and the digitaldata stored in the work storage; and a test section configured toperform a test of hypothesis based on a predetermined hypothesis usingthe degree of deviation.
 2. The system according to claim 1, whereinsaid work storage stores the digital data representing at least one of ashape, area, and color of a signature attached to the only one work; andsaid collation section calculates the degree of deviation betweendigital data representing at least one of a shape, area, and color of asignature attached to the target work and the digital data stored in thework storage.
 3. The system according to claim 1, wherein said testsection performs the test using a variance of the degree of deviation.4. The system according to claim 1, wherein said test section performsthe test using a mean of the degree of deviation.
 5. The systemaccording to claim 2, wherein said collation section calculates thedegrees of deviation for sub regions dividing the signature in a matrixmanner.
 6. The system according to claim 1, wherein said collationsection calculates the degree of deviation between digital datarepresenting the color in accordance with color fading and change ofcolor.
 7. The system according to claim 1, wherein said test sectiondetermines whether the target work is identical to the only one work. 8.The system according to claim 1, wherein said work storage stores thedigital data of plurality of only one works; and said test sectionsearches said work storage to find one of the only one works which ismost similar to the target work.
 9. A signature management systemcomprising: a signature storage configured to store signature datarepresenting signatures; a work storage configured to store work datarepresenting works; and a signature inserting section configured toinsert one of the signature data into one of the work data in responseto a request received through a network from a requester and distributethe work data into which the signature data is inserted to the requesterthrough, the network.
 10. The system according to claim 9, furthercomprising: a signature search section configured to collate a signaturedata of a target work to be identified and the signature data stored inthe signature storage in response to an identification request receivedthrough the network and returns a result of collation to the requesterthrough the network.
 11. The system according to claim 9, furthercomprising: a work search section configured to collate a work data of atarget work to be identified and the work data stored in the workstorage in response to an identification request received through thenetwork and returns a result of collation to the requester through thenetwork.
 12. The system according to claim 9, wherein said requestincludes data indicating a signature insertion position, and saidsignature inserting section comprises a determination section configuredto determine whether the signature insertion position indicated by therequest is a predetermined position which is approved by an author orowner of the work data and does not insert the signature data into thework data if it is determined that the signature insertion position isnot the predetermined position.
 13. The system according to claim 9,wherein said request includes data indicating a work use purpose, andsaid signature inserting section comprises a determination sectionconfigured to determine whether the work use purpose indicated by therequest is a predetermined purpose which is approved by an author orowner of the work data and does not insert the signature data into thework data if it is determined that the work use purpose is not thepredetermined purpose.
 14. The system according to claim 9, wherein saidrequest includes data indicating a signature insertion position and dataindicating a work use purpose, and said signature inserting sectioncomprises a first determination section configured to determine whetherthe signature insertion position indicated by the request is apredetermined position which is approved by an author or owner of thework data, a second determination section configured to determinewhether the work use purpose indicated by the request is a predeterminedpurpose which is approved by an author or owner of the work data, andinserts the signature data into the work data if it is determined thatthe signature insertion position is the predetermined position and thatthe work use purpose is the predetermined purpose.
 15. The systemaccording to claim 9, further comprising a search section configured tosearch said signature storage to find out one of the signature datawhich is most similar to an object signature data which is transmittedfrom the requester and returns a result of search to the requester. 16.The system according to claim 9, further comprising a search sectionconfigured to search said work storage to find out one of the work datawhich is most similar to a target work data which is transmitted fromthe requester and returns a result of search to the requester.
 17. Asignature management system comprising: a signature storage configuredto store signature data representing signatures; and a signatureidentifying section configured to collate an object signature datatransmitted from a requester through a network and the signature datastored in said signature storage and return a result of collation to therequester through the network.
 18. The system according to claim 17,further comprising: a work storage configured to store work datarepresenting works; and a work identifying section configured to collatea target work data transmitted from the requester through the networkand the work data stored in said work storage and return a result ofcollation to the requester through the network.
 19. The system accordingto claim 17, further comprising a search section configured to searchsaid signature storage to find out one of the signature data which ismost similar to the object signature data and returns a result of searchto the requester.
 20. The system according to claim 18, furthercomprising a search section configured to search said work storage tofind out one of the work data which is most similar to the target workdata and returns a result of search to the requester.